Department of Orthopedics, Beijing Geriatric Hospital, No.118 Hot Spring Road, Haidian District 100095, Beijing, China.
BMC Musculoskelet Disord. 2024 Mar 7;25(1):206. doi: 10.1186/s12891-024-07303-6.
Osteoporosis is a genetic disease caused by the imbalance between osteoblast-led bone formation and osteoclast-induced bone resorption. However, further gene-related pathogenesis remains to be elucidated.
The aberrant expressed genes in osteoporosis was identified by analyzing the microarray profile GSE100609. Serum samples of patients with osteoporosis and normal group were collected, and the mRNA expression of candidate genes was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The mouse cranial osteoblast MC3T3-E1 cells were treated with dexamethasone (DEX) to mimic osteoporosis in vitro. Alizarin Red staining and alkaline phosphatase (ALP) staining methods were combined to measure matrix mineralization deposition of MC3T3-E1 cells. Meanwhile, the expression of osteogenesis related genes including alkaline phosphatase (ALP), osteocalcin (OCN), osteopontin (OPN), Osterix, and bone morphogenetic protein 2 (BMP2) were evaluated by qRT-PCR and western blotting methods. Then the effects of candidate genes on regulating impede bone loss caused by ovariectomy (OVX) in mice were studied.
Cyclin A1 (CCNA1) was found to be significantly upregulated in serum of osteoporosis patients and the osteoporosis model cells, which was in line with the bioinformatic analysis. The osteogenic differentiation ability of MC3T3-E1 cells was inhibited by DEX treatment, which was manifested by decreased Alizarin Red staining intensity, ALP staining intensity, and expression levels of ALP, OCN, OPN, Osterix, and BMP2. The effects of CCNA1 inhibition on regulating osteogenesis were opposite to that of DEX. Then, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis demonstrated that genes negatively associated with CCNA1 were enriched in the TGF-beta signaling pathway. Inhibitor of TGF-beta signaling pathway partly reversed osteogenesis induced by suppressed CCNA1. Furthermore, suppressed CCNA1 relieved bone mass of OVX mice in vivo.
Downregulation of CCNA1 could activate TGF-beta signaling pathway and promote bone formation, thus playing a role in treatment of osteoporosis.
骨质疏松症是一种由成骨细胞主导的骨形成和破骨细胞诱导的骨吸收失衡引起的遗传疾病。然而，进一步的基因相关发病机制仍有待阐明。
通过分析微阵列谱 GSE100609 鉴定骨质疏松症中异常表达的基因。收集骨质疏松症患者和正常组的血清样本，通过实时定量聚合酶链反应(qRT-PCR)检测候选基因的 mRNA 表达。用地塞米松(DEX)处理体外模拟骨质疏松症的小鼠颅顶成骨细胞 MC3T3-E1 细胞。茜素红染色和碱性磷酸酶(ALP)染色法相结合，测量 MC3T3-E1 细胞基质矿化沉积。同时，通过 qRT-PCR 和 Western blot 方法评价成骨相关基因碱性磷酸酶(ALP)、骨钙素(OCN)、骨桥蛋白(OPN)、osterix 和骨形态发生蛋白 2(BMP2)的表达。然后研究候选基因对调节去卵巢(OVX)小鼠骨丢失的影响。
在骨质疏松症患者的血清和骨质疏松症模型细胞中发现细胞周期蛋白 A1(CCNA1)显著上调，这与生物信息学分析一致。DEX 处理抑制 MC3T3-E1 细胞的成骨分化能力，表现为茜素红染色强度、ALP 染色强度以及 ALP、OCN、OPN、osterix 和 BMP2 的表达水平降低。CCNA1 抑制对调节成骨的作用与 DEX 相反。然后，京都基因与基因组百科全书(KEGG)分析表明，与 CCNA1 负相关的基因富集在 TGF-β信号通路中。TGF-β信号通路抑制剂部分逆转了抑制 CCNA1 诱导的成骨作用。此外，抑制 CCNA1 减轻了体内 OVX 小鼠的骨量。
下调 CCNA1 可激活 TGF-β信号通路，促进骨形成，从而在骨质疏松症的治疗中发挥作用。
